Hi, I have an intermittent audio problem , but my head unit is fine, what goes on?

[cobalt 123456]

Hi all,

I have a 2005 chevy cobalt Lt, with factory pioneer
subwoofer in the trunk and factory pioneer speakers and I assume the factory amp under my steering wheel. I have an aftermarket kenwood
ddx 419 double din head unit installed.

I have a problem with my car audio volume. The first
20 minutes after I start my car, whether or not I have any
audio and for how long is totally random, it may play
immediately, it usually doesn't , it may come on for 10
seconds then disapear for 7 minutes before coming on
again, it may not work at all etc...but after 20-25
minutes it works for as long as my car ride takes.

Its NOT my head unit. I replaced it with another one
and I had the same problem

I had disconnected my onstar power module below my back
shelf because I don't use it and didn't like being
spied on, but I recently reconnected it to see if it
would fix the problem, it didn't.

Its not my battery, also just replaced.

my amp fuse located in the passenger well fuse box was
NOT blown, but its contacts WERE quite charred. I
replaced it, no change.

My head unit has power!! an mp3 shows an advancing time
index when it plays, my clock is always right. I'm just
not getting any sound...reliably anyway, for that first
20 minutes..

I was about to recrimp all the wires leading out of my
stereos main jack, when I decided not to for the time
being...I can't imagine how one or more than one being
improperly crimped could lead to an intermittant loss
of ALL audio...

I'm thinking theres a problem with my amp because of
the charring of its fuse, I was told though that a
blown amp or subwoofer can't be responsible for loss of
all audio, that the other speakers should still play,
but i'm heartened by this fellows posting on this very
site who says he lost all audio whenever his amp fuse
blew,

http://www.chevycobaltforum.com/forum/f11/factory-
pioneer-amp-fuse-keeps-blowing-solved-post-6-a-3682/

mine didn't blow, but this would suggest if my amp
isn't working properly then I would be getting no
sound. He and I don't seem to have exactly the same
problem, but its as close as i've found, I'm going to
look for his solution..still I suspect its not quite
the same.

I've never been able to find my stereos ground behind
the dash, so I've never been able to confirm that its
connected properly, still, the fact that my head unit
always has power suggests that it is, besides the fact
that my problem goes away after a time suggests a
thermal problem, like something has to warm up first
for the system to work (amp?, a piece of insulation
expanding or contracting out of the way to make a bad
wire make a connection?)

I also wondered if the onstar module that my head unit
is plugged into is failing..but I don't think so, I
push my onstar button to hear its demo, and while I
can't hear it because of my problem ..my head unit does indicate that its
playing..also I can hear it when my audio comes back later on...

I'm inclined to just remove or unplug my amp and see
what happens, is it as simple as that? wouldn't i have
to rewire the hole made in the system? I don't know how
to do that..same with the subwoofer..

all I really use my radio for is traffic and weather,

don't really care if i'm stuck with a sad underpowered
system.

any advice? whats the simplest way to bypass the amp? or any other thoughts?

thanks very much.

 

[YelloEye]

Your line above about OnStar, are you indicating that when your stereo cuts out, pressing the OnStar button is also silent?

What stereo adaptor are you using? GMOS-LAN-04?